102  
FXUS65 KBYZ 082117  
AFDBYZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BILLINGS MT  
217 PM MST THU DEC 8 2022  
   
DISCUSSION
 
 
TONIGHT THROUGH FRIDAY NIGHT...  
 
ACCORDING TO LOCAL GUIDANCE, TONIGHT HAS THE BEST CHANCE FOR  
ADVISORY STRENGTH WINDS IN THE GAP AREAS WITH A 40 PERCENT CHANCE  
AT KLVM. HOWEVER, NAEFS 700 MB WINDS WERE BELOW 40 KT AND FROM AN  
UNFAVORABLE DIRECTION OF WSW. ALSO NOTED THAT THE GFS SURFACE  
GRADIENT WAS RUNNING SEVERAL MB TOO STRONG LATE THIS MORNING.  
HOWEVER, GRADIENT LOOKED BETTER EARLY THIS AFTERNOON AND WINDS  
WERE PICKING UP AT KLVM. WILL ISSUE ADVISORY FOR GAP AREAS FOR  
TONIGHT. NOT SEEING ANY BLOWING SNOW ON WEBCAMS TODAY AND SNOW  
DEPTHS LOOKED LIKE THEY WERE BELOW AN INCH. THUS WILL REMOVE  
MENTION OF THE BLOWING SNOW IN THE WINDY AREAS TONIGHT. WILL HAVE  
CHILLY NIGHTS IN THE TEENS AND HIGHS JUST BELOW NORMAL FOR FRIDAY.  
 
SREF AND OTHER MODELS SHOWED AN UPPER TROUGH MOVING INTO THE AREA  
ON FRIDAY. THE TROUGH MOVES OFF TO THE E FRI. NIGHT AND UPPER  
RIDGING BUILDS INTO THE AREA. THE NBM SHOWED A 60 PERCENT CHANCE  
OF GREATER THAN AN INCH OF SNOW OVER THE SW MOUNTAINS FROM 12Z  
FRI.-12Z SATURDAY. TONIGHT WILL BE DRY, AND SNOW WILL BE LIKELY IN  
THE SW MOUNTAINS FRI. AFTERNOON WITH LESSER CHANCES IN THE CRAZY  
MOUNTAINS AND ADJACENT FOOTHILLS. SNOW CHANCES DECREASE FRI.  
EVENING. DID INCLUDE A 20 PERCENT CHANCE ON THE W SIDE OF THE NE  
BIGHORNS FRI. EVENING BASED ON GFS TIME-HEIGHTS. THE SNOW SHOULD  
BE DONE AFTER 06Z SATURDAY. SNOW AMOUNTS WILL RANGE FROM 1-3  
INCHES IN THE WESTERN MOUNTAINS. ARTHUR  
 
SATURDAY THROUGH THURSDAY...  
 
THE WEEKEND STILL LOOKS RELATIVELY QUIET AND MILD. SOME SHORTWAVE  
RIDGING WILL BUILD IN, WHICH COULD MAKE THE WINDS ALONG THE  
FOOTHILLS GUSTIER AGAIN, BUT LOCAL PROBABILISTIC GUIDANCE SHOWS A  
LOW PROBABILITY (<30%) OF REACHING 58 MPH. ALSO, LOOKING AT THE  
PRESSURE GRADIENT FROM IDAHO FALLS TO LEWISTOWN, THE GRADIENT  
GENERALLY LOOKS TO SUPPORT BREEZY CONDITIONS. TEMPERATURES WILL  
BE IN THE 30S FOR HIGHS AND UPPER TEENS FOR LOW.  
 
FOR REMAINDER OF THE EXTENDED THE FORECAST STILL HAS THE POTENTIAL  
FOR A SIGNIFICANT WINTER STORM, WITH POSSIBLE BLIZZARD CONDITIONS  
FOR SOUTHEAST MONTANA. THE MODELS CONTINUE WITH THE LOW COMING ON  
SHORE IN THE PACIFIC NORTHWEST SUNDAY, WHICH COULD START BRINGING  
SNOW TO THE WESTERN ZONES SUNDAY EVENING. THIS SNOW WILL SPREAD  
ACROSS THE REGION OVERNIGHT INTO MONDAY. AS THE LOW MOVES THROUGH  
SNOW WILL CONTINUE THROUGH AT LEAST WEDNESDAY. ALSO, AS LOW STARTS  
TO WRAP UP AS IT MOVES INTO THE CENTRAL PLAINS, WINDS IN THE  
ESPECIALLY THE SOUTHEAST START TO INCREASE, RAISING THE CHANCE  
FOR BLIZZARD CONDITIONS.  
 
AS IT CURRENTLY STANDS, AREAS WEST OF BILLINGS ARE IN THE 6 TO 8  
INCH RANGE, WHILE AREAS FROM BILLINGS EASTWARDS HAVE 8 TO 12 WITH  
SOME LOCALLY HEAVIER AMOUNTS. HOWEVER, THE NBM 1 IN 10 CHANCE  
HAS AMOUNTS EAST OF BILLINGS CLOSER TO 18 TO 24 INCHES. WHILE THIS  
A VERY UNLIKELY SCENARIO, THE POTENTIAL FOR HIGHER AMOUNTS IS  
THERE. THE SNOW EFFICIENCY SHOULD BE HIGH WAS THE SNOW GROWTH  
ZONE IS DEEP, WITH PLENTY OF LIFT, IN ADDITIONS TO UPSLOPE FLOW  
THAT COULD LOCALLY ENHANCE AMOUNTS. THERE IS STILL TIME FOR THE  
TRACK TO CHANGE, BUT GIVEN CONSISTENCY IN THE MODELS, CONFIDENCE  
IS INCREASING. THE NBM PROBABILITY FOR A FOOT OR MORE OF SNOW FROM  
MONDAY THROUGH WEDNESDAY IS NOW BETWEEN 40 AND 50 PERCENT. REIMER  
 

 
   
AVIATION
 
 
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. GUSTY  
SOUTHWEST WINDS AROUND 35-45 KNOTS ARE EXPECTED TO CONTINUE  
AROUND KLVM AND K6S0 TODAY. ARCHER  
 

 
   
PRELIMINARY POINT TEMP/POPS
 
 
FRI SAT SUN MON TUE WED THU  
-----------------------------------------------------------  
BIL 016/034 013/033 019/035 017/022 014/021 014/024 012/021  
01/E 00/B 01/E 58/S 75/S 44/S 32/S  
LVM 020/034 015/038 024/039 017/023 011/023 012/026 010/026  
02/S 11/N 14/S 87/S 42/S 22/S 22/S  
HDN 005/032 006/032 010/032 011/021 011/019 011/022 007/020  
00/E 00/B 01/E 39/S 87/S 65/S 43/S  
MLS 003/024 006/029 008/023 009/021 013/020 012/019 009/016  
00/B 00/U 00/B 16/S 88/S 77/S 42/S  
4BQ 011/033 013/036 016/035 013/023 012/018 012/020 009/019  
00/B 00/U 00/B 05/S 88/S 87/S 42/S  
BHK 010/031 009/031 014/030 011/023 014/022 011/018 007/016  
00/B 00/U 00/B 03/S 89/S 87/S 42/S  
SHR 010/034 010/035 018/039 013/023 009/020 010/023 007/022  
00/E 00/B 00/B 29/S 98/S 66/S 43/S  
 

 
   
BYZ WATCHES/WARNINGS/ADVISORIES
 
 
MT...WIND ADVISORY IN EFFECT UNTIL 5 AM MST FRIDAY FOR ZONES  
65-66.  
WY...NONE.  
 

 
 

 
WEATHER.GOV/BILLINGS  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MT Page
The Nexlab WY Page Main Text Page